Hi! And thank you!
Well.. i think we have restaurants figured out, so basically whats the big stuff (attractions/shows/night time fun etc.) to do?
Let me explain- I went there when i was 13 with my family but ill be going back when im 18 with a friend! Big difference and attention will be towards stuff more our age not family stuff. haha if that makes sense.
I recommend any of the rides that are "more extreme." By that, I mean the rides for the adventerous.
For example, in the Magic Kingdom, I'd ride Big Thunder Mountain Railroad, Space Mountain, and Splash Mountain. (The triple mountain whammy.) Haunted Mansion can be described as creepy, yet exciting. POTC is also a good ride, if you're into that. Don't forget to check out the classics, such as the Astro Orbiter (If you're not afraid of heights), Buzz, The Carousel, The Carousel of Progress, It's a Small World (if you're willing to have that song stuck in your head the rest of the day.

) And other rides like that.
EPCOT's "main" attractions include Mission: Space, Test Track, Space Ship Earth and Soarin'. I know that there are tons more, but I'm running short on time.
There's always Downtown Disney, the "shopping district" of WDW. There are tons of stores there, from Sporting Goods, to Ghiradelli, to Christmas shops. There's also Pleasure Island, the area of DTD that has clubs. I haven't been in them, since I think you have to be 18 or older to enter, anyway.
I suggest that you purchase the Unofficial Guide or Birnbaum's, because they are loaded with everything that "The World" has to offer.
I'll elaborate on a few other things later, if someone doesn't pick up where I left off. Byee.